The present invention relates to the use, for synthesizing or immobilizing nucleic acids, of a solid support modified with an organized self-assembled monolayer of one or more organosilicon compounds, and also to methods for synthesizing and immobilizing nucleic acids on a solid support.
To carry out chemical syntheses or immobilize molecules on an inorganic surface, it is, first of all, necessary to graft onto the surface coupling agents which will provide the attachment of the organic molecules to the inorganic substrates.
Organosilicon coupling agents have been proposed for this purpose by L. A. CHRISEY et al. (Nucleic Acids Research, 1996, 24, 15, 3031-3039) and U. MASKOS et al. (Nucleic Acids Research, 1992, 20, 7; 1679-1684). The agents used, namely 3-glycidoxypropyltrimethoxysilane and various aminosilanes, have, however, the drawback that they deposit randomly and nonreproducibly over the surface. They form a nonhomogeneous film thereon, the thickness of which, cannot be controlled, this film also not standing up very well to subsequent chemical treatments, the nonhomogeneity of the film in fact implying poor protection of the siloxane bonds. It is therefore very difficult to obtain reproducible grafting of these molecules. Before attaching or synthesizing oligonucleotides on the substrate, additional surface reactions are necessary to decrease the steric hindrance at the surface (for example grafting of bifunctional heterocyclic molecules, as described by L. A. CHRISEY et al.), to make the surface more hydrophilic (U. MASKOS et al. describe the grafting of ethylene glycol or penta- or hexaethylene glycol) and/or to overcome the poor reactivity of the surface functions, these being additional operations which, themselves, are also not controlled.
A. ULMAN described, in Chem. Rev., 1996, 96, 1533-1554, the formation of organized self-assembled monolayers on solid supports using organosilicon compounds of the functionalized alkyltrichlorosilane type. The use thereof for attaching biomolecules is proposed, this being a method which probably requires, in this context, modification of the biomolecule with a thiol function and modification of the surface with heterobifunctional molecules.